A code phrase referencing someone who, to put it ever so bluntly, is a royal flaming homosexual.
This gathering of multifarious verbiage comes from two sources.
San Fransisco aka Gay Mecca
Lumber Jack or one who chops down wood.
If your still confused about the definition read it again.
Hank: Dude, Stacey's boyfriend is pretty much a San Fransisco Lumber Jack.